CVE-2026-1513 is a security vulnerability classified under CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as cross-site scripting (XSS). It affects billboard.js, a popular open-source JavaScript charting library maintained by NAVER. The vulnerability exists because the library does not properly sanitize input when binding chart options, allowing malicious JavaScript code to be injected and executed in the context of the victim's browser. This can occur when untrusted data is passed to the chart configuration, which is then rendered without adequate escaping or sanitization. The vulnerability affects all versions prior to 3.18.0, which was released to address this issue. Exploitation requires an attacker to supply crafted input that is processed by the vulnerable library, potentially through user-generated content or manipulated data sources. The impact of successful exploitation includes theft of sensitive information such as cookies or session tokens, manipulation of the DOM, and execution of arbitrary scripts leading to account takeover or further attacks. No authentication is required for exploitation, and no user interaction beyond visiting a maliciously crafted page or content is necessary. Although no exploits have been reported in the wild, the vulnerability is significant due to the widespread use of billboard.js in web applications for data visualization.

For European organizations, the impact of CVE-2026-1513 can be substantial, especially for those relying on billboard.js for internal or customer-facing web applications. Successful exploitation could lead to unauthorized access to user sessions, data leakage, and potential compromise of user accounts. This can damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR violations due to data breaches), and result in financial losses. The vulnerability could be leveraged as an initial vector for more complex attacks, including lateral movement within corporate networks or deployment of malware. Organizations in sectors such as finance, healthcare, and e-commerce, where sensitive data is handled, are particularly at risk. Additionally, the vulnerability could be exploited to deface websites or disrupt services, impacting availability indirectly through reputational harm and user trust erosion.

The primary mitigation is to upgrade billboard.js to version 3.18.0 or later, where the vulnerability has been patched. Organizations should audit their web applications to identify usage of billboard.js and ensure no legacy versions remain in production. Implement strict input validation and sanitization on all user-supplied data before it is passed to chart configurations. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. Regularly review and update dependencies to incorporate security patches promptly. Conduct security testing, including automated scanning and manual code reviews, focusing on client-side libraries and their integration points. Educate developers about secure coding practices related to client-side scripting and data handling. Finally, monitor web application logs and user reports for signs of suspicious activity that could indicate exploitation attempts.